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    <script>
        var arr=[2,3,4,5]
        /* var newArr=arr.slice(0,)
        arr.push(5)
        console.log(newArr); // [2, 3, 4, 5] */
        var newArr=[].concat(arr)
        arr.push(6)
        console.log(newArr);// [2, 3, 4, 5]
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